"The message is very simple: to face reality and draw conclusions based on facts." Mariana Campeanu, Romanian minister for labour, was in no mood to mince her words last week.

Once again, as in 2007 when her country joined the EU, her country's workers are at the centre of a debate in Britain about the threat of benefit-seeking immigrants, fuelled by comments and briefings by government ministers keen for an easy headline, and apocalyptic statistics from Migration Watch about what will happen in 2014 when restrictions on working are lifted for Bulgarians and Romanians.

Seated in her large tatty Bucharest office, in what was once the Communist Central Committee Building where Nicolae Ceausescu made his fateful speech in 1989 from a balcony looking over what would become known as Revolutionary Square, Campeanu reeled off a list of statistics and appeals to common sense: Britain is behind Italy, Spain, France, Portugal and Germany as targets for her people. Those who wanted to live abroad now do so, with a million Romanians each in Italy and Spain. There are at most about 150,000 Romanians in the UK: 80,000 working in agriculture, 6,000 working as doctors or nurses and 5,000 as students. Most of the others are in construction or jobs requiring a high degree of education. A tiny, negligible number are without work.

Could we not, Campeanu implored, recall how the Romanian construction workers helped to build the Olympic stadium, a "special achievement"? Could we not see the benefits of the Romanians who had come to the UK? Why would we want to continue to make it difficult for highly intelligent young men and women to make homes there, she wondered? "I don't think it is normal that some restrictions are addressed only to Romanians and Bulgarians as long as we believe we are equal citizens in the EU," she said. "They must be against everyone, or no one."

There is trouble brewing in Revolutionary Square. Romania and Bulgaria burst into the political debate last week. Campeanu believes that it may be simply a chance for some British politicians to grab a few easy votes at a time when Europe bashing is in vogue.

It started with Tory MPs calling for the retention of a visa regime imposed in 2005 that restricts Romanians and Bulgarians to highly skilled jobs that cannot be filled by resident workers, or to seasonal agricultural work.

It escalated into reports that the UK government was considering producing negative adverts about Britain to put off migrants. Then Mark Harper, the immigration minister, raised the prospect of preventing some Romanian and Bulgarian workers from using the NHS, so that they would not be "a burden".

But these attacks on Romanian workers could not have come at a worse time, say Romania's politicians.

The country's economy is now in its fifth year of decline, according to a former prime minister, Calin Popescu-Tariceanu, who brought the country into the EU. The popularity of the EU has inevitably waned since the country joined the club on 1 January 2007, when there were raucous parties in Revolutionary Square and nearby University Square. The economic crisis has not helped, of course, and if Britons have their gripes about the EU banning bent bananas, then the Romanians are irritated that they can't slaughter the family pig at Christmas and Easter in the traditional throat-slitting way.

But it is not the content of the grumbles that matters, but the very fact that they circulate. There is a growing feeling that the major EU states and the European commission are not taking Romania's needs into account. Last week the latest European commission report on Romania's integration into the EU complained about a lack of progress in fighting political corruption, in what was seen by many as a fresh blow to Romania's dignity. Most importantly, the EU has prevented the Romanian government from increasing its relatively small public debt to invest in infrastructure to try to reduce the gap between their country and the western giants. All this blocking and snubbing, Tariceanu says, is dangerous. "An economic crisis can have a very important social impact and then of course come the political tensions and conflicts and all the rest. How long will the patience of the people last?"

Talking from one of the echoing rooms of the Palace of the Parliament, built to be the former dictator's palace, Tariceanu adds that Britain's attitude will inevitably only add to the frustrations of many Romanians – including himself. "I am living with a certain disappointment," he said. "Why? Because I am looking at Great Britain as a country that is a reference for the democratic and liberal spirit.

"I know that the European project has been built around four crucial liberties: the freedom of movement of goods, services, people and capital. I am pretty sure the UK is very much supporting the free circulation of capital, which is not only in its own advantage but everyone's.

Key waves of UK immigration. Credit: Observer graphics

"But they have to reconsider their position because the free circulation of people is essential for the welfare of Britain. What is making me angry is that it is a planned government campaign against the immigrants. I was not expecting it from a country with such long traditions of democracy and freedom." The Observer has learned that such is the anger within the Romanian government at the recent rhetoric that the foreign minister, Titus Corlatean, sought and received assurances last week from his counterpart, William Hague, that the UK would live up to its treaty obligations. The UK ambassador to Romania was also, in a most diplomatic way, asked about his government's position by Cristian David, the minister for Romanians abroad, who asked for facts, figures and rational balanced discourse to rule the day on the subject. David said: "We need to communicate with our people in a balanced and rational way. If we leave an open space for media to interpret figures, it can allow another perception which can be very difficult to erase."

Former Romanian president Ion Iliescu, the first democratic leader after Ceausescu, told the Observer: "I am waiting for better understanding from Britain for the problems faced by Romania and Romanians." But the concerns and disappointment of the political classes is merely a reflection of the feelings on the streets outside their offices.

Revolutionary Square today bears little resemblance to the scene on the sunny December day in 1989 when the crowds, to the old dictator's obvious surprise, turned on him, causing his flight, capture and execution just four days later on Christmas Day. Much of the square is now a car park for those who work in the ministries of labour, interior and sanitation, among others, that are now housed within the former Communist Central Committee building.

On one of the buildings marking out the north side of the square, a banner advert for a bank bears the face of former tennis star Ilie Nastase. On the south side is a shop selling Swiss watches so expensive that the prices aren't advertised. Shuffling across the icy square itself, by a monument for those killed by the old regime, are a few disgruntled workers and students voicing, perhaps not anger at this stage, but disappointment and bitterness.

"Things are worse than ever in the EU. Nothing has changed for the better," said Sorin Sonie, 38. "I don't want to leave because I love my country, but I do think it is very unfair for the UK to try and stop people if they want to go and live there. Why us?"

Parking attendant Julien Pirvulescu, 56, said: "I think it is more about politics. I don't want to go and my three children in their 20s don't want to go. People here aren't interested in rushing off there. But it is unfair. It often is."

Vlad Niculesci, 45, who runs an English bookshop on the west side of the square, added: "There is growing anger because it is discriminatory across the board. The artist Dan Perjovschi, one of the best in Romania, has just done a drawing which is simply a picture of the union flag with all its crosses next to one big, black cross under which is written: for Romanians and Bulgarians. That sums it up."

Perjovschi, exhibiting in Helsinki, explained: "It is always an irritation when you are questioned as a nation. And when media step in, anger increases or may go out of control. Facebook is full of mockeries of Brits and some superficial 'patriotic' feelings.

"On the other hands, Romanians love the Premiership, Robbie Williams and Helen Mirren, and the visual artists are obsessed with Tate Modern. Romanians had a great respect of UK because legend says that Tony Blair contributed massively to our EU bid. Therefore the actual situation is seen as a betrayal."

The inherent danger in this growing feeling of iniquity provoked the Romanian ambassador to the UK, Dr Ion Jinga, speaking from London, to warn of the risks in politicians and some parts of the media "playing a game" with the Romanian people. He told the Observer: "Sometimes tabloids, and unfortunately some politicians, try to involve this topic of immigration from Romania and Bulgaria in a political game and gamble.

"But those Romanians who wanted to work abroad have already done it. Seven years ago our population was 22 million inhabitants. Last year the census showed we have only 19 million because 3 million were already abroad. With a country of 22 million inhabitants there are only 5 million people of an economically active age in Romania, so we experience shortages and have organised job fairs in Spain and Italy to try and convince Romanians in construction to come back. We have reached the maximum export capacity.

"And in 2004, the British economy had an economic boom, which is not the case now. I do not see any real risk of a big wave of Romanians coming over."

Jinga added that it was only a demand for Romanian workers that would lead them to travel across Europe to a country whose language many were not well versed in and whose culture was so alien. He said: "The Olympic village of the last Olympic Games was built by Romanian builders, even if the construction sector was closed to Romanians. Not because they came to take British jobs but because there were not enough British builders to work and they were asked to come and they became self-employed."

Jinga said he sees the rhetoric around the immigration of Bulgarians and Romanians as pure electioneering. And he is withering about the reported plan to wage a negative advertising campaign to put Romanians off, said by sources to have now been ditched under diplomatic pressure. Jinga said: "My interpretation is that it is very connected to a political situation: some anti-European speeches and some positioning before the election so that every possible risk is closed. But there is no risk to Britain.

"It is up to the British government to decide on what sort of campaign you want to promote for your country. If you ask me as a person who spent the last five years here and is very honestly in love with this country, I would not do it. In Romania we would never do a negative campaign about Romania saying to foreigners, 'Don't come, it's rubbish.' If you want to do it, it is up to you. It would be a pity."

Either way, it would seem that the British government now has its work cut out to make things right with the people in and around Revolutionary Square.